Shortly after the referendum on 23 June, demands were made that continuing EU membership should now be considered by Parliament, with a view it seems to stop BREXIT happening, and to frustrate the will of the 17 million who voted to leave. Indeed, the Guardian carried an article only five days later on ‘How we can stop Brexit – lobby our MPs’ (29 June 2016), no doubt as inflammatory and unacceptable to the BREXITEERS as subsequent developments have been to the REMAINERS. Fearing that Parliament was being enlisted with an agenda to defeat the referendum result, it is not surprising that the BREXITEERS should wish to exclude Parliament from the process altogether.

Even better if they could find legal authority to implement the referendum result that would not require Parliament’s formal input until much later in the process. So we discover only 12 days after the referendum that ministers had been ‘advised by the Government lawyers that, in their view, it clearly is a prerogative power’ (HC 431, 2016-17, Oral evidence, Q 86). The ‘it’ to which Mr Oliver Letwin is here referring is the decision to trigger Article 50. In view of the fact that the government was notoriously unprepared for BREXIT, the period between 23 June and Mr Letwin’s appearance before the Foreign Affairs Committee on 5 July seems an awfully short period of time in which to produce such a considered, authoritative and conclusive view.

And so it proved to be, with the High Court delivering a historic blow to the government on 3 November, holding that there is no prerogative power to trigger Article 50. This is a decision that wrong-footed almost everyone, a court in Northern Ireland having held only a week earlier that there was no legal basis for judicial intervention to stop the government (Re McCord’s Application [2016] NIQB 85). The widespread scepticism about whether the courts had the grounds to intervene, and if they did whether they would have the courage to do so, fuelled the over-confidence on the side of the BREXITEERS, which was so rudely shattered by the High Court to the evident dismay of those planning to leave.

The High Court decision is nothing if not brave, for the judges must have anticipated the growling response from an insurgent press in full spate, the shock troops in the BREXIT wars, and others besides. It was now the turn of the REMAINERS to be appalled by inflammatory remarks in the press, which in some quarters labelled the judges who delivered judgment in Miller v Secretary of State for Exiting the EU, as ‘enemies of the people’ (Daily Mail, 4 November 2016). Equally unacceptable was the abuse heaped upon the claimants in a frenzy led by the Daily Mail, the Daily Express and the Daily Telegraph, a frenzy to which even the Prime Minister herself is alleged to have contributed (The Independent, 3 November).

II

The most surprising feature of the Miller decision is the narrow grounds on which the Article 50 question was dealt with. The decision addressed the sole ground that the government has prerogative authority to trigger Article 50, perhaps because public statements had been made by ministers to this effect at a time when they should have remained silent until the legal position had been more carefully considered. As the High Court has made clear there is no question that the government cannot change domestic law by means of prerogative power: Constitutional Law 101.

This should have been known from the experience of joining the European Community in the first place, a process which took three steps: the Treaty of Rome had to be signed; it had then to be ratified; and it had then to be implemented (in the last case by the European Communities Act 1972). The first of these steps is perhaps the parallel step to what is now Article 50, and it is not without irony that those who were opposed to EEC membership demanded that Parliament not only have sight of the accession treaty, but also the right to approve it before it was signed.

But in rejecting this demand, the then Solicitor General (who was in favour of EEC membership) relied on constitutional orthodoxy in saying that

Throughout, the treaty making power resides in the Crown, in Her Majesty the Queen acting upon the advice of her Ministers. It is by virtue of the Royal Prerogative in the conduct of foreign affairs that the Government initiate, sign and ratify international agreements. As a matter of constitutional law, no parliamentary authority is necessary before the Crown may exercise those powers. The other principle is equally important. Those prerogative powers, the treaty-making powers, do not enable the Crown to alter the law within the United Kingdom so as to implement the treaty. This internal implementation—this is an important point about which the House can be entirely reassured—is fundamentally distinct from the making or the conclusion of the treaty. If a treaty includes an alteration of our domestic law, including the granting of new powers to the Crown or the undertaking of new financial commitments, then Parliamentary approval in the form of appropriate legislation is necessary before the objectives of the treaty can be met. (H C Debs, 20 January 1972, col 793-4. Emphasis added.)

So there was no need for parliamentary approval before the treaty was signed, because the treaty would have no effect in domestic law. The treaty would in due course be laid before Parliament as required by the Ponsonby rule (now Constitutional Reform and Governance Act 2010, s 20), and would be implemented subsequently by the 1972 Act.

The key point here, of course, is not that the government has prerogative power to sign treaties, but the implicit limitation of that power. The Solicitor General could confidently claim the existence of such a power because as he said, signing the treaty would not change the law, however curious it might seem that he would want to deny Parliament a vote. When we come to BREXIT, however, the position is different in the sense that triggering the exit process will itself affect legal rights, as is explained by the High Court in Miller. But quite apart from the sometimes tortuous analysis in the case, the rights which will be directly affected are those Treaty provisions which have direct horizontal effect.

In these cases – notably the right to equal pay in TFEU, Article 157 – the right is clear and unequivocal (Case 43/75, Defrenne v SABENA [1976] ECR 00455). By virtue of Article 50, treaty provisions will cease to have effect after two years from the date the trigger is pulled. It is true of course that Treaty provisions have effect by virtue of the 1972 Act, and that in principle the 1972 Act could remain on the books long after Article 50 is invoked. But the fact is that by virtue of the European Union (Amendment) Act 2008, the treaties to which the 1972 Act NOW applies are the TEU and the TFEU, including Article 50 of the former, which makes it clear that ALL treaty provisions will normally cease to apply after two years of Article 50 being triggered.

It is thus clear that as a matter of basic constitutional law the prerogative power is not wide enough to do what Oliver Letwin claimed before the House of Commons Foreign Affairs Committee, and that government lawyers were ill-advised to suggest otherwise. The point is well made by the long line of authority cited in Miller. There is a clear need for parliamentary authority to trigger Article 50, and almost certainly a need for that authority to be in the form of primary legislation. It would be a high risk to assume that a resolution of either or both Houses is sufficient authority to amend, repeal or dis-apply an Act of Parliament. The question then is whether that parliamentary authority ALREADY exists, making it unnecessary for the government to seek fresh legislation.

I must confess that I had thought that a general power to this effect already existed in the 1972 Act (as amended by the European Union (Amendment) Act 2008, which incorporated the TEU into domestic law). TEU, Article 50 authorises ALL member states, INCLUDING the United Kingdom, to withdraw in accordance with their own constitutional requirements. As a matter of constitutional practice, foreign affairs in this country are initially an executive act, the main requirement being that these powers cannot be exercised to change the law without parliamentary authority. But by incorporating Article 50, Parliament has provided that authority and government power to withdraw as a matter of domestic law. The 2008 Act’s incorporation of Article 50 was not referred to by the court save only to say that the government had argued that it did not restrict the prerogative power of the government. My understanding is the opposite: the 2008 gave power to the government.

Parliament did not confer that general power on government to withdraw subject to the condition that Parliament should be required to approve any decision to exercise the power, though it had the chance to do so. Although Parliament might generally expect to be consulted before a statutory power of this magnitude is exercised, on this occasion Parliament effectively waived any such claim by agreeing to hold a referendum, strengthened by the fact that it was a manifesto commitment of the governing party, strengthened still further by a clear undertaking in the latter manifesto that the government would be bound by the result, whatever its outcome.

III

Beyond the narrow point of the decision, the Miller case raises a number of other significant issues. The first has been the media and ministerial reaction, which shows a clear failure by the former to understand the basic constitutional principles by which this country is governed, and a clear failure by the latter to discharge their legal responsibilities (Constitutional Reform Act 2005, s 3: ‘The Lord Chancellor, other Ministers of the Crown and all with responsibility for matters relating to the judiciary or otherwise to the administration of justice must uphold the continued independence of the judiciary’). So far as the press is concerned, the reaction to the Miller decision was rabid – attacking not only the litigants but also the judges who were pilloried on the front pages of what have become little more than propaganda sheets for UKIP.

In the words of former Attorney General Dominic Grieve, the coverage was reminiscent of Mugabe’s Zimbabwe (The Guardian, 5 November 2016). It is designed no doubt to intimidate the judges. At the time of writing, the Daily Mail had already started on the Supreme Court, exposing one of its members as a ‘feminist and a longstanding critic of marriage’ (Daily Mail, 4 November 2016), neither obviously relevant in the Article 50 debate. What is lamentable about this coverage is not only the nature of the attacks, but the ignorance by which they are fuelled. I have in mind here the ignorance of the constitutional history and principles of the country whose ‘independence’ the BREXITEERS purport to defend.

What the High Court did was to assert the basic constitutional rule that the governments of this country cannot change legislation by executive fiat. That is uncontroversial. It is unclear, however, whether this is a power that the right wing press would like the government to possess, which some might think would be usefully employed against those who appear to demand it. The zealots should be careful of what they wish for, and perhaps reflect also on their own contribution to constitutional principle, which on one famous occasion included lending support and succour to Mosley and his fascists (see Roy Greenslade, ‘Don’t Damn the Daily Mail for its Fascist Flirtation 80 Years Ago’, The Guardian, 6 December 2011).

So far as ministers are concerned, they ALL have a responsibility to protect the independence of the judiciary. The ink on the decision was barely dry when one minister referred to the case as ‘an attempt to frustrate the will of the British people and it is unacceptable’. In the face of the personal attack on judges by the press, the Ministry of Justice chose initially not to make a statement. Yet the Lord Chancellor has a personal duty over and above that of other ministers to safeguard judicial independence, a principle which the current incumbent is only slowly beginning to understand. When a statement was finally made by the Lord Chancellor, it was criticised as being too little, too late, an anodyne remark about judicial independence failing to address the specific issues (The Observer, 6 November 2016). This led to a third response, this time eventually defending the integrity of the Lord Chief Justice (The Guardian, 7 November 2016).

In a parliamentary rather than a populist democracy it is elected politicians and not invisible proprietors and camera-shy editors who make the law. Which of course raises a second issue raised by Miller, namely the fissure between the people and Parliament which the decision has exposed. It may well be that our existing constitutional principles do not sufficiently accommodate the growing use of referendums as an instrument for the resolution of differences between us. But that being the case, it is certainly no answer to say that the referendum was only ‘advisory’ as the REMAINERS claim.

As already pointed out, David Cameron made it clear, when he gambled the future of his country on the narrow sectarian interests of his party (not to mention his own self-interest), writing in the Conservative Party General Election Manifesto in 2015 that he would be bound by the outcome of the referendum, whatever the result. The fact that neither he nor anyone else expected the outcome delivered does not make that commitment any less binding. Nor can it plausibly be claimed that MPs who supported the referendum did so on the basis that their support for it was conditional on the outcome.

In my view Parliament provided the power to BREXIT (as explained above) and determined the means by which that power might be used (the Referendum Act 2015), and in my view Parliament’s fingerprints are already all over the process. It does not follow from this, however, that the High Court was wrong in its treatment of the referendum, even though it did not have the legal effects that BREXITEERS obviously expected and demanded. It comes back to the narrow issue before the court. The fact that there was a referendum does not give the government the power by prerogative to take away statutory rights.

Nor in any event should BREXIT be left to the government to decide. The BREXITEERS and their attack dogs claim far too much when they say that the referendum gives the government a blank cheque to deliver whatever kind of BREXIT the government wants rather than what the PEOPLE want. When all is said and done, the referendum result was not overwhelming, and while it gave a mandate to BREXIT, it gave no mandate as to the form of BREXIT, and certainly no licence for a BREXIT determined exclusively by Messrs Davis, Fox and Johnson.

IV

Which brings us to the third issue to arise from the Miller decision, namely the wider political implications. Some talk of a constitutional crisis. That seems silly. There is no constitutional crisis, the constitution is flexible enough to adapt to whatever will be thrown at it, however uncomfortable the journey may be for some political actors. But the decision will almost certainly unlock a savoury political problem for the government, if it is upheld by the Supreme Court.

The current political climate is so unpredictable that it is pointless trying to speculate about what will happen in the immediate future. There are, however, no doubt some MPs who would have preferred not to have been given this opportunity to exercise their sovereignty, MPs who will now be pitted against a majority of their constituents. There will also be a number of MPs who will be leaving Parliament after the next election, unconstrained by the need to tailor their behaviour to the demands of re-election. Adding to the uncertainty is another ill-judged Cameron initiative, namely the proposed boundary changes.

The only thing that is certain is thus that any BREXIT Bill will enter a House of Commons at a time of great uncertainty within the House, a time when in addition the House has been empowered by the creation of a new select committee with a powerful chairman. It can be expected that while the House will support the Bill, that support will not be unconditional and that proper scrutiny will now take place on the government’s proposals in a way that ministers had hoped to avoid. But if the purpose of BREXIT was to reclaim parliamentary sovereignty, how can this be wrong?

The role of Parliament in these circumstances is thus not to block BREXIT but to mediate the views of the people and the wishes of government. Parliament has a duty to ensure that the voices of ALL the people are heard, and that BREXIT takes place in the national interest, not the sectarian interest of the Conservative Party or a section thereof. People of all parties voted for BREXIT, and those on the left have a very different vision of BREXIT and different aspirations from those on the right. The voice of the left is a voice that not everyone will feel properly represented by the hapless ministers now in charge.

A potentially more serious problem for the government than the House of Commons is what happens in the House of Lords where there are reports that a majority of peers are for REMAIN. The political power of the House of Lords is greatly under-estimated by modern accounts of its role. For the most part the House of Lords is kept in check by the Salisbury Convention, whereby it will not frustrate the business of the government designed to implement manifesto commitments (see A W Bradley, K D Ewing and C J S Knight, Constitutional and Administrative Law (16th ed, 2015), pp 205-7). It is strongly arguable of course that a BREXIT Bill will thus be covered by Salisbury. But will the Lords see it in these terms?

The Lords can refuse to pass the BREXIT Bill, and can insist on amendments that the government is unwilling to accept. True, the government can invoke the Parliament Acts 1911-1949 to get its own way. But that would mean not only another bruising encounter in the Commons, but also a delay of perhaps a year. One thing the government does not have is the luxury of time. Any delay in the House of Lords will take us dangerously close to the general election in 2020 (assuming the government has not collapsed before then), and an election that will be rerun of the 2016 referendum.

The House of Lords thus has real power in this unfolding drama, should it wish to exercise it, and the capacity to cause real damage to a BREXIT Bill, should the Supreme Court uphold the High Court. New battle-lines would then be drawn: it would be the peers against the people. Again it seems unlikely that the House of Lords would vote against, though who can say at this stage? And although the Lords would nevertheless be ill-advised to block the Bill altogether, there is absolutely nothing the government can do to restrain the real political power of the unelected second chamber.

The spectre here of course is the controversy of 1909, in which the hereditary peers famously rejected Lloyd George’s People’s Budget, leading to demands for the creation of enough peers to get the Budget through, two general elections in 1910, and the subordination by law of the legal powers of the Lords. A basic knowledge of history may lead the existing generation of Lords to put institutional self-preservation ahead of individual grand-standing. The irony will nevertheless not be lost of unelected judges unleashing the power of the unelected Lords to block the direct democracy of the referendum.

V

The High Court decision in Miller has brought into sharp focus at least three basic constitutional principles: the rule of law, the independence of the judiciary, and the sovereignty of Parliament. So far as the last is concerned, it has addressed the core question that the government does not have prerogative power to BREXIT. That is the easy question. But it leaves unanswered the more difficult question whether the government has statutory power to BREXIT by virtue of the European Communities Act 1972, as amended by the European Union (Amendment) Act 2008. For this purpose, I am assuming that Article 50 contains powers within the terms of the 1972 Act, s 2(1).

That said, there is no doubting that BREXIT has unleashed great political uncertainty. It has done so by piling contradiction upon contradiction, irony upon irony, expediency upon expediency, inexpediency upon inexpediency, and hypocrisy upon hypocrisy – in other words it is piling politics upon politics. To these ends it is striking that the BREXITEERS wish to contain the voice of Parliament when their forbears, the OUTERS, 45 years ago demanded and were denied a parliamentary vote. And conversely striking that the REMAINERS should be demanding the opposite when the INNERS then in government refused a vote 45 years ago.

Equally striking is the demand of the BREXITEERS for a repatriation of parliamentary sovereignty and the ultimate authority of the British courts, yet the hydrophobic response from those making these demands when the British courts assert the sovereignty of the British Parliament in accordance with the British constitution, the basic principles of which the BREXITEERS so plainly misunderstand. The supreme irony of course is that if there is legal authority to do what the BREXITEERS want to do, it will arise, admittedly by virtue of an Act of Parliament, but an Act of Parliament that gives effect to EU law, on which the BREXITEERS’ case must lie.

Temperatures need to cool on both sides, and a lot of ignorant people in positions of authority and influence need to take time out to learn some constitutional law. An opportunity perhaps for Law Schools in the new era of commercialisation? Miller is a hiccup rather than a mortal blow to the ambitions of the BREXITEERS, and while it is right that the referendum result is respected, it is also right that the referendum result is not a blank cheque for Theresa May and her colleagues to negotiate whatever deal they want (or whatever deal they can). It would, however, have been more seemly if Parliament had asserted its sovereignty earlier, and got off its knees without having to be told to do so by the High Court.

K D Ewing, Professor of Public Law, King’s College London

This is an abridged version of the editor’s introduction of the forthcoming special issue of the King’s Law Journal on BREXIT.